Geoethical tsunami fiasco
A.D. AhluwaliaTHE Sumatra quake which unleashed tsunami waves in Indian Ocean resulted from ocean floor rupture over 1200 kilometres long with three sub-faults extending from Nicobar upto northern Indonesia subduction zone.
The deadliest quake of history was in Chile in 1960 and measured 9.5.
In spite of tsunamis, hardly a hundred were killed.

Understanding
the UniverseWith Prof Yash PalQ. When I move my fingers rapidly in front of the TV screen, why do I see multiple images?A.There is nothing special about your fingers. A pencil will do just as well. In a normal TV, the picture frame is refreshed 24 times a second. That is how motion is perceived.

THE Sumatra quake which unleashed tsunami waves in Indian Ocean resulted from ocean floor rupture over 1200 kilometres long with three sub-faults extending from Nicobar upto northern Indonesia subduction zone.

The deadliest quake of history was in Chile in 1960 and measured
9.5. In spite of tsunamis, hardly a hundred were killed. The entire damage in the historical records caused by quakes and tsunamis in the Pacific region is not a patch on mayhem wreaked in the Indian Ocean.

That the Indian Ocean tsunamis are unknown is a myth. Total 10 deadly tsunamis are known in the Indian Ocean from 1762 onwards i.e. 1819, 1883, 1904, 1907, 1926, 1941, 1945, 1977, 1994 and upto 2004. It is not the first but the fifth time that Indonesia region has faced a tsunami disaster.

Tragedy actually got compounded because of: i) lack of a Tsunami warning system in the region; ii) failure of scientists across the world to analyse the massive foreshocks shaking Indonesia in the recent weeks and prognosticate about eventualities in the event of more massive earthquakes which in oceanic regions generate tsunamis.

Tsunamis in spite of their massive speed and energy took long hours after quake to reach one by one areas beyond Indonesia and Andamans. Quakes never kill people but the unwise and/or corrupt builders do. Tsunamis are even more innocent than earthquakes because these afford a huge reaction time even when there is no sophisticated warning system laid out all over the area. Was it not the geoethical failure on part of those who understood and knew all the pros and cons of the foreshocks and major shock to alert governments in South Asia and advertise in the media? This question has been ducked.

Tsunamis took so many hours to kill or wound so many in the region in the year 2004 yet our planet managers could know only after disaster.

Indian Ocean tragedy is not totally due to lack of a warning system but attributable to the dumb reaction of our scientists as well as administrators. A strict scientific auditing of reactions of various seismic geophysical establishments to all earthly warnings is warranted. Mere telephonic communications between various regions or hotline activation between various governments after the tsunamis set going, would have saved lots of lives at least in Thailand, Sri Lanka, and India and beyond.

We may network the entire region soon for tsunami warnings. But there never was and never would be any substitute to a 24 hour per day and 365 days a year wake vigil by conscientious men and women monitoring earthquakes and scientifically studying these physical changes.

Abundant awakening of public and governments to earthquake and tsunami mysteries is another prerequisite to an effective warning system. The understanding must percolate to a panchayat level if we are to cope with such disasters in future effectively and squarely.

Nature has multiple eloquent ways of giving out warnings. It is not the tsunamis which resulted in recent Indian Ocean tragedy but the complacent scientists or vacationing babus across the Indian Ocean who really are the killers. This tribe would be again sleeping when next tsunami ever comes. If 30 to 100 minutes time is considered an insufficient reaction time in Indian Ocean during broad day light, we cannot ever effectively react to any disaster anywhere.

THE bones of beached whales show signs of decompression sickness — the “bends” suffered by deep-sea divers — which scientists believe could explain why some sea mammals are stranded en masse.

A study of the skeletons of sperm whales has found that many of them suffered from a type of bone damage normally associated with the bends, when bubbles of nitrogen form in the blood causing pain and distress. The findings lend support to the theory that loud underwater noises produced during naval exercises using submarine sonar could startle whales and dolphins and cause them to surface more rapidly than they would normally.

For years, marine biologists have believed that sea mammals are somehow immune to decompression sickness but the latest study, published in the journal Science, forms part of a growing body of evidence suggesting this is not the case.

Michael Moore and Greg Early, of the Woods Hole Oceanographic Institution in Massachusetts, found extensive damage, called osteonecrosis, to the bones of stranded sperm whales.

They suggest that this could support the idea that sea mammals in general are vulnerable to becoming stranded when they are startled into rising too soon from a deep dive.

“The long-held dogma of complete immunity to decompression sickness in marine mammals should be revisited,” the scientists say. “It therefore appears that sperm whales may be neither anatomically nor physiologically immune to the effects of deep diving,” they say. Sperm whales can dive more than two miles in the search for their quarry - giant squid - and any sudden rise to the surface could in theory cause dissolved nitrogen to come out of solution as gas bubbles.

If these bubbles form in the tissues they can cause acute pain by pressing against nerves and blocking small blood vessels, resulting in the muscles being starved of oxygen. When this happens in bone, small areas of the tissue can die, leading to the formation of tiny cavities.

Q. When I move my fingers rapidly in front of the TV screen, why do I see multiple images?

A. There is nothing special about your fingers. A pencil will do just as well. In a normal TV, the picture frame is refreshed 24 times a second. That is how motion is perceived. This is also true of motion picture recording and projection. In between frames, is a short period when the screen goes blank. This is the period when the scanning beam of electrons moves from the bottom of the screen to the top so as to start a new scan. Our eyes do not notice the scan or the blanking period partly because of slow decay of light from the phosphor on the screen, but mostly because of the phenomenon of persistence of vision. (Perhaps persistence of vision is also due to another slow decay — namely that of the signal coming to the visual cortex from the sensors at the back screen of the eye)

Thus, when you shake your finger (or a pencil) in front of a computer or TV screen, it is in effect going across a source of light that varies in intensity 24 times a second. This leads to broken and separated images of the finger. While typing these words, I tried to estimate the number of separate images I saw while rapidly sweeping my finger across the computer screen. I estimated that every second I was doing four traversals and I saw nearly six fingers during each passage. So, without any additional equipment, I could say that the illumination of my screen fluctuates about 24 times a second. Try it.

Incidentally, you may also be able to demonstrate, with a similar measuring technique, that the tube light in your home or office fluctuates nearly 50 times a second. This is the frequency of the alternating current (AC) electric supply in India.

Q. When air is expelled from the mouth in a gentle stream, it is kind of warm, but when expelled under pressure, it feels quite cool. Why?

A. Our body temperature is usually higher than that of the ambient atmosphere. The air that we let out while exhaling slowly is at that temperature. I am sure that the temperature of the exhaled air would be slightly higher than the equilibrium temperature of our skin body. After all, this air comes straight from the spots where fires of life are burning, using the oxygen in the breath intake.

On the other hand, when we blow out air through a small opening between compressed lips, we are subjecting it to another operation. First, we compress the air, increasing its pressure. Any increase in temperature is easily neutralised while passing through the passages inside the respiratory tract. When the air is expelled at a fast rate through the narrow opening between our lips, it expands. Like most gases, the expanding air cools. This is because energy is required to pull molecules away from each other. That is what the Boyle’s law is all about. This explains your observation.

Flexible
electronics technology has the potential to replace hard electronic devices such as flat-panel displays, bringing advantages such as light weight, low power consumption and flexibility.

Most work on these systems uses hydronised semiconductor silicon (a-Si:H) and organic semiconductors, but performance has been inefficient for use as transistors in practical applications in computers. A team at the Tokyo Institute of Technology, Japan, has now developed an alternative semiconductor material that may help in bridging performance gap.

It’s an amorphous oxide semiconductor from the In-Ga-Zn-O (IGZO) system, and it has been used to make transparent thin-film transistor at room temperature. The devices perform well and, have the potential to outperform those based on a-Si:H.

They are also well suited to integrate with other materials used in flexible transparent electronic circuits.
— S.P. Gupta

White light technology

In days to come, cost-effective white Light-Emitting Diode (LED) technology will change the way cities and houses are lit up everyday after twilight, eminent scientist C N R Rao said.

‘’The white LEDs coated with Gallium Nitride (GaN) will bring about a lighting revolution as traditional bulbs and solar lamps will become a thing of the past,’’ says Professor Rao, the honorary President of Bangalore-based Jawaharlal Nehru Centre for Advanced Scientific Research. ‘’This technology is presently used in cheap small flash torches available in the market,’’ the professor said, trying to relate the technology to some of the practical applications.

‘’The white light technology is cost-effective as significant energy saving is possible,’’ he said, adding ‘’The devices have a superior life-span and will not blow out as a traditional bulb or incandescent lighting does.’’
— UNI

Stem cells and Parkinson’s

Stem cells taken from tiny monkey embryos and implanted in the brain reversed some of the Parkinson’s symptoms in monkeys used to study the disease, Japanese have researchers have reported.

Their study, published in the Journal of Clinical Investigation, supports arguments that stem cells taken from days-old embryos can be used to replace damaged tissues in a range of diseases, experts said.
— Reuters

Missing cosmic link

A team of UK and Australian astronomers today announced that it has found the missing link that directly relates modern galaxies like our own Milky Way to the Big Bang that created our Universe 14 thousand million years ago.

The findings are the result of a 10-year effort to map the distribution in space of 220,000 galaxies by the 2dFGRS (2-degree Field Galaxy Redshift Survey), a consortium of astronomers, using the 3.8-m Anglo-Australian Telescope (AAT).

This missing link was revealed in the existence of subtle features in the galaxy distribution in the survey.

Analysis of these features has also enabled the team to weigh the universe with unprecedented accuracy.